• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.138-147
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• 2020

Various microorganisms play important roles in food fermentation, food spoilage, and agriculture. In this study, the biotype of 54 yeast and bacterial strains having high potential for utilization in food and agriculture, including Candida spp., Lactobacillus spp., and Acetobacter spp., were characterized by matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS). This characterization using a fast and robust method provides much-needed information on the selected microorganisms and will facilitate effective usage of these strains in various applications. Importantly, the unique protein profile of each microbial species obtained from this study was used to create a database of fingerprints from these species. The database was validated using microbial strains of the same species by comparing the mass spectra with the created database through pattern matching. The created reference database provides crucial information and is useful for further utilization of a large number of valuable microorganisms relevant to food and agriculture.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.67-73
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• 1988

This study was conducted to isolate etiological agents from the 103 scouring piglets in Gyeongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical served. The incidence of scouring piglet was most prevalent as 81.6% in the age of 2 to 4 weeks after birth, while the rate was less than 10% in the age of 5 to 6 weeks and under 1 week after birch. When compared the isolation frequency of the each etiological agent, enteropathogenic E. coli was most prevalent as 46.6%, thermophilic Campylobacter 26.2% and Salmonellae was 8.7% in order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85 (20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni were belong to type I (50.0%) and II (25.0%), and most strains of C. coli were belong to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C. and each 1 strain was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, wherease about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C.jejuni and C. coli were sensitive to kanamycin and gentamicin.

• International Journal of Oral Biology
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• v.31 no.1
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• pp.7-10
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• 2006

Mitis-salivarius sucrose bacitracin(MSB) medium is widely used in the selective isolation of mutans streptococci(MS), a designation for a group of oral cariogenic species. Recently, we have isolated three bacterial strains grown on MSB agar from human dental plaques. The three strains exhibited biochemical characteristics similar to those of the biotype IV of MS, with the exception that they manifested a positive reaction for arginine deaminase. The objective of this study was to identify and characterize these three clinical isolates. The bacteria were identified with biochemical tests as well as by 16S rDNA cloning and sequencing. In order to compare the antibiotics susceptibility of the clinical isolates with that of type strain, the minimum inhibitory concentrations of 9 antibiotics were determined using broth dilution assays. The results identified all of our three clinical isolates as Enterococcus faecalis. All E. faecalis strains were found to be susceptible to penicillin G, amoxicillin, augmentin, and vancomycin, but were resistant to ciprofloxacin, cefuroxim axetil, and clindamycin. Our findings indicate that E. faecalis is capable of growing on MSB agar, and suggest that the MSB medium be improved so that only MS should be recoverable on the medium, as originally devised for their selection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.365-372
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• 2012

Native of soybean aphid (Aphis glycines Matsumura) is an Asia and aphid is one of the dangerous pests in soybean [Glycine max (L.) Merr.]. High density aphid populations can reduce crop production by causing severe damage. The objective of this study was evaluation of resistance to the soybean aphid in soybean cultivars and germplasms. A total of fifty five soybean cultivars or germplasms, including two susceptible and two resistant check varieties, were infested to evaluate their resistance in the field cage and greenhouse test by aphid colonies which derived from wild collected one soybean aphid biotype in Korea. The average number of reproduced soybean aphid was evaluated with 62.7 aphids in the resistant check variety PI 567598B and also estimated with 1,807 aphids for susceptible check variety Williams 82. In soybean varieties and germplasms, the average reproduced soybean aphid populations ranged from the lowest 497 aphids for Junjeori to the highest 3,862 aphids for Mansu. About seventy six percent of soybean cultivars and germplasms were shown high density soybean aphid populations when compared with another susceptible check variety PI 567543C in the field cage test. From the greenhouse test to evaluate aphid index, 87.3% of soybean cultivars or germplasms presented aphid index with 9.0. No soybean cultivars and germplasms were observed with soybean resistant phenotype when regarded a aphid resistant level as less than 10% aphid reproductions compared with susceptible check Williams 82. Although no Korean soybean cultivars were identified with resistant trait to the soybean aphid, we found one great resistant genetic resource PI 567598B in this study. This result will be helpful to further study for providing useful genetic information for soybean researchers.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.674-678
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• 2002

Yersinia enterocolitica causes various diseases in humans, including enteritis. The onset of such diseases is closely related with the expression of important virulence factors, particularly outer membrane proteins (OMPs). The expression of OMPs depends on several factors, including temperature, and origin, biotype and serotype of the bacteria. Recently, concerns over food safety have increased along with the demand for the development of sensitive, rapid, and pathogen-specific detection methods. To develop a suitable detection method for Y. enterocolitica isolated from Korean moutainspring water and pig feces, the OMP expression patterns were analyzed phenotypically and immunologically using 12 representative strains from 51 Y. enterocolitica Korean isolates. A 38-kDa OMP was commonly observed in all strains. However, additional OMPs were also observed in different biotypes and serotypes as well as bacterial origins, by incubating Y. enterocolitica at a low temperature. The specificity of the 38-kDa OMP was confirmed by a Western blot analysis with antisera against Y. enterocolitica and Brucella abortus. The results, therefore, indicate that the 38-kDa OMP could be used as a marker for detecting Y. enterocolitica in the environment or for seromonitoring.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.192-198
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• 2011

This study was conducted to investigate the herbicidal activity against Scirpus planiculmis (SCPPL) which has been reported as resistant biotype on sulfonylurea (SU) herbicides at the west coast reclaimed area first and proliferated continuously at Hwasung and Pyeongtaek in Gyeonggi province, and some Chungnam province. In order to investigate resistance breakability against SCPPL, new rice herbicides containing tefuryltrione [p-hydrophenyl pyruvate dioxygenase (HPPD) inhibitor], pyrimisulfan and triafamone[actolactate synthethase (ALS) inhibitor] were tested. In both lab and field experiments, tefuryltrione GR, 4-HPPD inhibitor showed growth retardation with a bleaching on the young leaves of SCPPL at early time after treatment. However, it restored and regerminated with insufficient control effect. On the other hand, pyrimisulfan+mefenacet SC, triafamone+tefuryltrione GR, and ALS inhibitor showed excellent control effect on SU-resistant SCPPL with growth retardation and necrosis. In particular, pyrimisulfan+mefenacet SC showed excellent controlling effect on SU-resistant SCPPL in regional field experiments.

• Journal of Environmental Health Sciences
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• v.24 no.1
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• pp.141-150
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• 1998

This study was performed to investigate the distribution of Yersiniae and correlation between Yersiniae and indicator organism by time and area in spring water located in northern part of Seoul. Samples collected from 46 spring waters located in four mountains(Dobong, Bukhan, Surak, Bulam) were inspected to detect Yersiniae and indicator organisms. And also there were examined bioserological characteristics and resistance of ahtibiotics of the isolated Yersiniae.The result were as follows. 1. The isolation rate of Yersiniae was 22% in February and 20% in April. The isolated species were 6 strains of Y. enterocolitica, 6 strains of Y. aldova, 4 strains of Y. intermedia and 43 strains of Y. pseudotuberculosis. The serotype of Y. pseudotuberculosis isolated from was all O:5 and biotype of Y. enterocolitica isolated from was all O:3. 2. The Geometric mean of standard plate count, coliform, and psychrotrophilic bacteria were 3.4 CFU/ml, 1.2 MPN/100 ml and 33.0 CFU/ml in February and 3.1 CFU/ml, 1.5 MPN/100 ml and 20.5 CFU/ml in April respectively. There was no significant difference by time and area but the indicator organisms were correlated significantly with each other (p<0.05). 3. Because detection of Yersiniae was not statistically associated with indicator organism, Yersiniae can be detected in the spring water approved microbiologically (p<0.05). 4. The Yersiniae isolated were resistant to Ampicillin, Colistin, Carbenicillin and Coilstin. All isolaed Y. enterocolitica were resistant to Ampicillin (100%). In the case of Y. pseudotuberculosis, only 1 of 3 isolated was resistant to Colistin but susceptible to other antibiotics.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.117-124
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• 2010

Members of the genus Brucella are facultative intracellular bacteria and cause brucellosis, a chronic disease in humans and abortion in animals. In this study, we tested sera for brucellosis of 15 Hanwoo farms in the western part of Gyeong-buk province, resulting 5 farms were brucellosis positive in 2008. We collected blood from 277 heads in the brucellosis positive 5 farms, and performed serological diagnosis, brucella positive cattle which had shown higher than 200 antibody titer in tube agglutination test were slaughtered, supramammary lymph nodes were collected, and Brucella spp. wild type isolation and identification were performed. From these results, 15 of Brucella spp. wild type strains were isolated and all strains were identified as B. abortus biotype 1 by biological and molecular analysis. In the antimicrobial susceptibility test, all 15 strains had a similar susceptibility and resistance pattern. This study may be useful for bacteriological and epidemiological understanding of cattle brucellosis in Korea.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.133-138
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• 2012

This study was conducted to investigate the herbicidal activity against resistant biotype on sulfonylurea (SU) herbicides such as Scirpus juncoides and Monochoria vaginalis at the glasshouse and paddy rice cultivation area. In order to investigate resistance breakability against SU-resistanted annual weeds, new rice herbicides containing tefuryltrione [p-hydrophenyl pyruvate dioxygenase (HPPD) inhibitor] were tested. In both lab test and field experiment, tefuryltrione mixture, 4-HPPD inhibitor had shown excellent efficacy with a bleaching on the leaves of resistant annual weeds at early time after treatment and showed excellent persistance. Especially, tefuryltrione mixture had shown excellent controlling effect on annual and perennial SU-resistant S. juncoides in the regional field experiment. In phytotoxicity test, this tefuryltrione mixture had shown good selectivity to common rice species.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.73-78
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• 2001

Yersinia enterocolitica is an inhabitant in the lower intestinal tract of many domestic and wild animals as well as in the nature. Of the several forms of diseases caused by Y. enterocolitica, an acute enteritis, especially in young children, is the most common form. Infection of the bacteria usually occurs through fecal-oral route by contaminated foods or water, especially mountainspring water. Of the domestic animals, swine has been known as one of the most important carrier in the human infection. Based on the knowledge, prevalence of antibody against Y enterocolitica was investigated with swine sera collected from Korea for the survey of Y enterocolitica infection in swine. As the first step of this survey, we analyzed outer membrane protein (OMP) profiles of the representative strains of Y enterocolitica isolated from the feces of piglets and mountainspring water in Korea. Thirty-eight kDa OMP was identified as the common OMP regardless of origin, serotype, or biotype of Y enterocolitica isolates. Presence of antibody specific for 38 kDa OMP of Y enterocolitica in 1,076 swine sera collected from November 1999 to October 2000 was analysed with ELISA. Antibody titer in sows was significantly higher than that in piglets, growing pigs and finishing pigs (p<0.05). Also, there was seasonal difference in the prevalence of antibody against Y enterocolitica. These results would provide the basic knowledge for controlling the Y enterocolitica infection in human as well as swine.